• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.417-425
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• 2005

KOINONIA is high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. A KOINONIA piconet is a collection of one or more associated slaves under a single master. Efficient scheduling of a master for the traffic of slaves is essential to use channel effectively and to guarantee QoS of multimedia traffic. We propose a new scheduling algorithm to allocate channel time at desired intervals regardless of superframe length, and a Connection Admission Control(CAC) algorithm to regulate the number of traffics in a piconet. Our proposed algorithms have been shown to save channel time and to meet QoS requirements compared to the conventional weighted round-robin algorithm.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.10-23
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• 2016

With requiring circumspections using big data, this study attempts to develop and apply the search method for audit issues relating to the ITS policy or program. For the foregoing, the auditing process of the board of audit and inspection was converged with the theoretical frame of boundary analysis proposed by William Dunn as an analysis tool for audit issues. Moreover, we apply the text mining technique in order to computerize the analysis tool, which is similar to the boundary analysis in the concept of approaching meta-problems. For the text mining analysis, specific model we applied the antisymmetry-symmetry compound lexeme-based LDA model based on the Latent Dirichlet Allocation(LDA) methodologies proposed by David Blei. The several prime issues were founded through a case analysis as follows: lack of collection of traffic information by the urban traffic information system, which is operated by the National Police Agency, the overlapping problems between the Ministry of Land, Infrastructure and Transport and the Advanced Traffic Management System and fabrication of the mileage on digital tachograph.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.79-88
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• 2008

VMS based dispersion of traffic flows enables to decrease delay and congestion. Such being the case, there has been growing interests in VMS operation strategy. The strategy is based on driver's behavior or diversion rate. However, it was not easy to obtain each in practice. The diversion rate, thus far, was investigated by stated preference analysis or simulators. As an alternative, in this paper, a new method to obtain diversion flow rate was suggested using the toll collection system and freeway traffic management system data. A large gap of diversion rate between stated preference analysis and field survey was observed. Out of surveyed 8 tollgate data, the diversion rate was about 7% and was quite lower compared with that of 21%${\sim}$87% from stated preference analysis or simulators. With this at hand, a more careful information provision strategy should be devised and employed to correctly account this kind of differences.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1238-1244
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• 2001

Earlier efforts on optical access concentrated on the design of PONs for the collection and distribution portion of the access network. In these networks the optical hardware in the RN is very simple, but a multiple access protocol is needed for upstream traffic control. On the other hand, the role of communications is already well established in the office environment. With the advent of cheap, affordable broadband communications and the increasing complexity of consumer electronics, it seems natural to extend the network into the home. As the application of Home Area Network is ever increasing, we therefore consider connectivity between access network and home network which generates various traffic to design MAC protocol over residential network. Global-FIFO is quite simple and allows dynamic upstream bandwidth assignment on the basis of a request-and-permit mechanism. It has good bandwidth efficiency and being cell-based, it does not consider the various traffic from home network. In this paper, we design and analyze the new MAC resource assignment algorithm called MQ-FIFO (Multiple Queue-FIFO) that provides good performance under the environment of ATM-PON and Home Network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.110-112
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• 2010

Because the building of new meteorological observation towers requires high cost, a collection of precise meteorological data over city area is not easy. To collect atmosphere environment data or meteorological data precisely, a new approach is required. This paper introduces a new meteorological data collecting system using the public traffic systems such as regular route bus. On real time, the regular route bus can provide a meteorological data in periodic time interval and provide them on static route. Without constructing new facilities, only simple sensing and transmission equipments to attach on the bus are needed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.485-492
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• 2010

Intelligent Transport System(ITS) has been studied in various systems, such as road environment information offering, vehicle short-range wireless/wire communication, vehicle collision preventing and pedestrian safety offering systems. Related to this, the USN technology based on the sensing accuracy for motorists and pedestrians safety, the information reliability, the maintenance and convenience for Sensor Network is highlighted. This study uses various sensors to construct USN to the road, and connect it to the developed RSU so it collects the real-time road environment information and offers it to OBU and Traffic Control Surveillance Center with Road Weather Information System. RSU collects roadside information for driver's safety and analyzes it to offer IP and beacon service according to the service priority to OBU & upper layer terminal. In the upper layer terminal it is developed the IP based Settop Box application program to offer the urban traffic information & road environment, and environment sensor error, etc. Finally, RWIS develops the real-time collection of roadside information to complement the driver's safety to the intelligent traffic system, and presents various service modes with technology convergence.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.4
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• pp.323-329
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• 1995

The number of motor vehicles in Korea has increased to about 4 million, and the exhaust gases of these vehicles have become a more threatening factor to public health. Traffic policemen are one of the highest health risk groups since they work on roadsides where they are exposed to high levels of air pollutants. The health effects on them due to air pollution were determined by measuring personal carbon monoxide(CO) exposure and carboxyhemoglobin(COHb) level in blood. Thirty-one traffic policemen in Seoul volunteered to be subjects of the study. In October 1992, personal CO exposure was measured by a CO passive sampler. The subjects wore the CO passive sampler for 8 hours while on duty. The exposed samples were analyzed by gas chromatography. Blood samples from each subject were collected just after the exposure sampling, and were analyzed within 3 hours of blood collection by a CO-oximeter. The activities of the subjects were recorded by the subject in 30 minute intervals using an activity log sheet containing location and time spent. Personal CO exposure were ranged between 0.1 and 14.5ppm, eith an average of 5.9ppm. Carboxyhemoglobin levels ranged from 1.1% to 6.9%, with an average of 3.6%. policemen on duty outdoors had significantly higher CO exposures and COHb levels than policemen on duty indoors(p<0.01). Personal CO exposure and COHb were positively correlated, although the coefficient was not significant. The relationship between CO level and COHb level was confounded by smoking status. Among smokers, COHb level was significantly higher as CO exposure and hours worked outdoors increased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.206-207
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• 2023

Intelligent maritime traffic information services provide services for maritime traffic safety, but due to the difference in ship specifications and loading condition, the method of determining abnormalities in ship stability has not been generalized. In this study, we established a method for collecting and preprocessing Accelerometer and GPS data for calculating ship stability. In addition, we have researched a model that can determine the real-time ship stability through data science algorithms that can reflect each vessel specifications and external forces, breaking away from approximate calculations that cannot reflect weather factors in the real ocean.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.52-63
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• 2009

Recently in Korea, in the case of metropolis, the urban signalized intersections are controlled by traffic information center or ITS center. Cheon-an City also established traffic information center through the 1st.-$\sim$3rd. ITS public construction and has managed this center that includes bus information service, traffic information collection and providing service, parking information service, and traffic responsive control system. In the Cheon-an metropolitan traffic signal operation, traffic signal controllers were grouped by the each main traffic flow axes and performed with coordinated signal timing for the signalized arterials, and also cycle and split changed by realtime traffic demands. Cheon-an urban traffic responsive control system was evaluated by intersection delay and speed, then it was verified that the delay decreased and vehicle speed improved. However, the rural signal control system to connect adjacency town was evaluated to have lower status than urban area due to the unimproved TOD (Time of day) plan. Therefore actuated signal control was examined for substitutive control system in isolated signal intersection. The aim of this article is to compare actuated signal control with TOD mode in the rural intersection of Cheon-an and to fine superiority of these two control mode, with evaluation of vehicle delay by using HCM(2000) method and by micro-simulation CORSlM. The result of field test show that actuated signal control gave better performance in delay comparison than the existing TOD signal control. And simulation outcome verified that non-optimized TOD has higher delay than optimized TOD mode, non-optimal actuated mode, and optimal actuated signal control mode. Particularly, these three modes delays had not different values according to the paired sample t-test. This is because small traffic demands were loaded in each links. This suggested actuated signal control is expected to be more effective than TOD mode in some rural isolated intersections which frequently need to survey for traffic volume.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.1-14
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• 2014

The expansion of the physical road in response to changes in social conditions and policy of the country has reached the limit. In order to alleviate congestion on the existing road to reconsider the effectiveness of this method should be asking. Currently, how to collect traffic information for management of the intersection is limited to point detection systems. Intelligent Transport Systems (ITS) was the traffic information collection system of point detection method such as through video and loop detector in the past. However, intelligent transportation systems of the next generation(C-ITS) has evolved rapidly in real time interval detection system of collecting various systems between the pedestrian, road, and car. Therefore, this study is designed to evaluate the development of an algorithm for queue length based real-time traffic signal control methodology. Four coordinates estimate on time-space diagram using the travel time each individual vehicle collected via the interval detector. Using the coordinate value estimated during the cycle for estimating the velocity of the shock wave the queue is created. Using the queue length is estimated, and determine the signal timing the total queue length is minimized at intersection. Therefore, in this study, it was confirmed that the calculation of the signal timing of the intersection queue is minimized.